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In Vitro and In Vivo Screening of Water Associated with CAFOs and Wastewater Treatment Plants for Estrogenic and Androgenic Activity
Citation:
CAVALLIN, J., L. WEHMAS, DAN VILLENEUVE, M. D. KAHL, K. M. JENSEN, E. A. MAKYNEN, E. J. DURHAN, C. LALONE, L. THOMAS, S. SKOLNESS, AND G. T. ANKLEY. In Vitro and In Vivo Screening of Water Associated with CAFOs and Wastewater Treatment Plants for Estrogenic and Androgenic Activity. Presented at SETAC North America 31st Annual Meeting, Portland, OR, November 07 - 11, 2010.
Impact/Purpose:
The paired in vitro and in vivo assays used for these studies provide insight into whether simple in vitro assays with recombinant human cell lines are useful for predicting the relative potencies and effects that complex mixtures of endocrine active chemicals may elicit in exposed fish.
Description:
The trend toward using concentrated animal feeding operations (CAFOs) to efficiently increase food production has prompted concern regarding the impact these feedlots have on the environment. Depending on the type of feedlot, animal waste from CAFOs can contain natural and synthetic androgens or estrogens which have the ability to pollute surrounding waterways during rainfall runoff events. In these studies we estimated relative androgenic and estrogenic activity (using the MDA-kb2 and T47D-Kbluc cell assays respectively) in stream surface water collected from various CAFO basins. In vitro cell assays were paired with 48 h static-renewal in vivo exposures to simultaneously examine potential endocrine-disrupting effects in male and female fathead minnows. Mature fish were exposed to four surface water dilutions (0%, 25%, 50%, and 100% surface water), and 50 ng 17â-trenbolone (TRB)/L and 10 ng 17á-ethynylestradiol (EE2)/L were used as in vivo reference chemicals. Gene expression and gonadal ex vivo testosterone (T) and 17â-estradiol (E2) production were examined after 48 h of exposure. Exposure to surface water from a dairy basin had no significant effect on male ex vivo T production. Results of the corresponding cell assays for this experiment suggested there was estrogenic activity in the sample, as determined by T47D-Kbluc assay. However, the MDA-kb2 assay did not detect androgenic activity in the surface water from this site. These CAFO studies were modeled after several paired in vivo and in vitro experiments using wastewater treatment plant effluent containing estrogenic compounds. Fathead minnows were exposed to four effluent dilutions (0%, 10%, 50%, and 100% effluent) in a similar 48 h static-renewal design, with different effluent samples over a three month period. Based on T47D-Kbluc assay results, the estrogenic activity of the effluent ranged from 1.13 to 2.00 ng (E2) equivalents/L. Corresponding in vivo studies demonstrated that male fish exposed to 100% effluent had significantly increased hepatic vitellogenin (vtg) and estrogen receptor á subunit (esr1) transcript abundance relative to controls. The paired in vitro and in vivo assays used for these studies provide insight into whether simple in vitro assays with recombinant human cell lines are useful for predicting the relative potencies and effects that complex mixtures of endocrine active chemicals may elicit in exposed fish.